Steam slide-valve



(No Model.)

H. R. GAMPPIEL'D'.

Steam Slide Valve. No. 231,651. Patented Aug, 31,1880.

WITNESSES I INVENTOR:

ATTORNEY N.PETERS, PHOTQ-UTHOGRAPHE w T for the exhaust-steam,

UNITED STATES PATENT OFFICE.

HAMPTON R. GAMPFIELD, OF SUSQUEHANNA DEPOT, PENNSYLVANIA.

STEAM SLI DE-VALVE.

' SPECIFICATION forming part of Letters Patent No. 231,651, dated August 31, 1880. Application filed July 9, 1880. (No model.)

To all whom it may concern:

Be it known that I, HAMPTON R. CAMP- FIELD, a citizen of the United States, residing at Susquehanna Depot, in the county of Susquehanna and State of Pennsylvania, have invented certain new and useful Improvements in Steam Slide-Valves; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification, in which Figure 1 shows a longitudinal section of a valve constructed according to my improve ment at the beginning of the exhaust, and Fig. 2 a similar view with one of the inlet-ports just opened.

This invention relates to that class of valves in which additional passages for the exhaust are used; and it consists in the peculiar construction of the valve, as hereinafter set forth, and then pointed out in the claim.

y invention consists in such a construction of the valve that the passage may be used whereby the cylinder maybe exhausted with great rapidity, and thus much back-pressure is prevented, thereby removing a source of much diffieulty and loss of power where steam is used under high expansion with the ordinary valve.

In the drawings, A represents a valveseat, provided with the ordinary inlet and exhaust ports; and B, the valve, having, in addition to the exhaust-cup a, the passage 1), arranged to connect theinlet-ports with the exhaust. The partition 0, dividing the cup afrom the passage b, has its bottom tapered down to a knife-edge, whereby the rapidity of the exhaust when it first begins is considerably increased.

When the valve has reached the position shown in Fig.1 the exhaust has begun, and owing to the use of the passage 11, there is double the amount of space for the exhaust that there would be without it, and by the time the valve has reached the position shown in Fig. 2 there is, in addition to the usual exhaust-space, an amount equal to the area of the passage 1), whereby the exhaust opening is doubled almost immediately.

By this construction the valve is built much cheaper and lighter than is that form where there are two exhaust-cavities with an additional exhaust-passage over each, and there is much less friction, because the central division in the valve and its seat are dispensed with, and the valve can therefore be made much smaller, leaving less surface for the steam to bear on.

What I claim as new is- The combination, with the valveseat A, of the valve B, provided with the single exhaustcavity a and the passage 12, extending from one inlet-port to the partition between the other inlet-port and the exhaust-port, and having the partition 0 between the cavity a and the passage 1) tapered to a knife -edge at its lower ends, substantially as and for the purpose specified.

In testimony whereof I affix my signature in presence of two witnesses.

HAMPTON 1t. OAMPFIELD. Witnesses T. J. W. ROBERTSON, H. A. HALL. 

